Behavioral Activation (BA) for depression is an empirically supported psychotherapy with a long history dating back to the 1970s. To date there have been no systematic reviews of how BA treatment packages and their accompanying components have evolved over the years. This review sought to identify and describe the specific treatment components of BA based on the descriptions of techniques provided in empirical articles on BA and referenced treatment manuals when available. The following component techniques were identified: activity monitoring, assessment of life goals and values, activity scheduling, skills training, relaxation training, contingency management, procedures targeting verbal behavior, and procedures targeting avoidance. The implementation of these techniques is reviewed, along with their empirical support both as stand-alone components and as components of larger treatment packages. Whereas activity scheduling, relaxation, and skills training interventions have received empirical support on their own, other procedures have shown effectiveness as parts of larger treatment packages. Although BA interventions differed in tools used, activity monitoring and scheduling were shown to be constant components across interventions. Possible directions for the future evolution of BA are discussed.